This invention relates to article grading methods and apparatus and in particular but not solely to optical scanning methods and apparatus used in the grading and/or packaging of fruit and/or vegetables.
Apparatus for the grading of fruit is known which includes a fast moving single stream grading conveyor with an endless circuit of carriers or cups for holding individual items of fruit. It is known to pass the hit on the fast moving conveyor through an imaging zone, where while being rotated on the carriers or cups, the fruit are optically scanned to analyse for example the fruits"" colour so that the fruit may for example be colour graded. It is also known to weigh each cup to ascertain the presence and, if present, the weight of items in each cup. This information may then be used to discharge the fruit carried by the individual cups into appropriate discharge lanes for packing.
Apparatus such as this has the disadvantage that for high speed operation the grading conveyor must move very rapidly and the scanning can produce blurred, fuzzy or less accurate images.
Apparatus for grading fruit is also known which has a multiple stream singulator for supplying fruit to the single stream grading conveyor. The multiple stream singulator has the desired effect of spreading fruit supplied to it in an even manner, such that fruit arriving at the single stream grading conveyor arrives in a fairly steady supply, and therefore the utilisation of the single stream grading conveyor, in terms of the number of filled cups per the total number of cups is higher than would be the case without the multiple stream singulator. However, currently known multiple stream singulators have advancing rows of effective cups delivering fruit to a discharge zone from where the fruit is then received by the grading conveyor, and each row of it on the singulator is delivered to the discharge zone simultaneously, and consequently the fruit arrives at the discharge conveyor in bunches. This has the disadvantage of not being a particularly steady flow.
It is therefore an object of the present invention to provide a method and/or apparatus for article grading which go some way towards overcoming the above disadvantages.
Accordingly in one aspect the invention consists in a method of scanning items to be graded which comprises
presenting the items to be scanned and graded to a singulating means adapted to advance multiple streams of the items to a discharge zone,
receiving onto a single stream grading conveyor from said discharge zone the discharged items of the multiple stream singulating means,
scanning the multiple streams of the singulating means for at least one discernable characteristic of each item and feeding output signals from said scanning to discharge control means of said single stream grading conveyor and
for each item associating said at least one discernable characteristic of said item with the position of said item on said single stream grading conveyor.
In a further aspect the invention consists in apparatus for scanning items to be graded comprising
means to in use present the items to be scanned and graded to a singulating means adapted to advance multiple streams of the items to a discharge zone,
means to receive onto a single stream grading conveyor from said discharge zone the discharged items of the multiple stream singulating means,
means to scan the multiple streams of the singulating means for at least one discernable characteristic of each item and feed output signals from said scanning to discharge control means of said single stream grading conveyor and
means to, for each item associate said at least one discernable characteristic of said item with the position of said item on said single stream grading conveyor.
In a still further aspect, the invention consists in a method of scanning items to be graded which comprises
presenting the items to be scanned and graded to a singulating means adapted to advance multiple streams of the items to a discharge zone,
receiving onto a single stream grading conveyor from said discharge zone the discharged items of the multiple stream singulating means,
scanning the multiple streams of the singulating means for at least one discernable characteristic of each item and feeding output signals from said scanning to discharge control means of said single stream grading conveyor and
ensuring between the discharge of the multiple stream singulating means at the discharge zone and the uptake from the discharge zone by said single stream grading conveyor a preservation of the sequence for the items determined during the scanning of the items.
In a still further aspect, the invention consists in apparatus for scanning items to be graded which comprises
means to present the items to be scanned and graded to a singulating means adapted to advance multiple streams of the items to a discharge zone,
means to receive onto a single stream grading conveyor from said discharge zone the discharged items of the multiple stream singulating means,
means to scan the multiple streams of the singulating means for at least one discernable characteristic of each item and feed output signals from said scanning to discharge control means of said single stream grading conveyor and
means to ensure between the discharge of the multiple stream singulating means at the discharge zone and the uptake from the discharge zone by said single stream grading conveyor a preservation of the sequence for the items determined during the scanning of the items.
In a still further aspect the invention consists in a multi-stream singulator comprising at least two streams of cups, at least one of said streams of cups being a partial cup in advance of the other streams of cups,
such that concurrent advancement of said streams of cups to a discharge zone causes items carried on said cups of said at least one partially advanced stream to be discharged non-simultaneously with items carried on said cups of said other streams.